The present invention relates to a pneumatic level control system in a motor vehicle, which latter comprises a vehicle battery and a generator supplying the vehicle battery, and an electrically operated compressor with an electric motor, which compressor is assigned to the level control system, the electric motor of the compressor being supplied with power by the vehicle battery and/or the generator only under certain conditions.
Various level control systems for motor vehicles are known from the prior art. Thus, for instance, a motor vehicle is known from DE3601176C1 which has a pneumatic level control system supplied by an electrically operated compressor. In order to prevent the battery from becoming prematurely exhausted, which is a concern in the case of constant supply of the compressor with electrical energy via the battery of the motor vehicle, the compressor is operated, in the case of a stationary internal combustion engine and upon reaching or falling below a lower level limit value, only when the trunk of the motor vehicle is open.
This has the disadvantage that, if a motor vehicle with level control system is loaded in some other way, for example through the front passenger or a rear side door, the vehicle may find itself leaning to one side, a situation which is not then corrected while stationary. Furthermore, despite this restriction there is still a risk of the battery of the motor vehicle being very heavily loaded, and possibly overloaded, by the level control system in the event of level compensation when the trunk lid is open, so leaving other safety-relevant systems with insufficient energy available to them.
The object of the invention is therefore to avoid overloading the vehicle battery of the motor vehicle through operation of the level control system.